Parametric investigation on the growth of ternary MnIn2Te4 thin films for photovoltaic application

Mn–In–Te thin films were electrodeposited on SnO2 coated glass substrates from an aqueous acidic solution containing MnSO4, InCl3 and TeO2. Cyclic voltammetric analysis of MnTe, In2Te3 and MnIn2Te4 was carried out to understand co-deposition potential and the growth mechanism was studied. The potential region for single step growth of stoichiometric and highly crystalline MnIn2Te4 thin film was investigated. Thus formed films were characterized for structural, compositional, electrical and optical properties as a function of the deposition potential applied for the film growth. MnIn2Te4 films growth show an optical energy gap of 1.6–1.7 eV in the as-deposited state. Increase in optical transmission of MnIn2Te4 film on annealing is accompanied by a change in absorption coefficient from 7.2×104 to 1.5×104 cm−1. Electrodeposited MnIn2Te4 films are semiconducting and current conduction follows space charge controlled mechanism. Studies of C–V characteristics of p-MnIn2Te4/n-CdS heterojunction yields carrier density of ∼8×1018 cm−3.